I'm also interested if you have sleep working Tony.
I would be surprised if it were. I had a look at the apple developer pages and it says that the only USB dongle they
semi supported was a certain revision of a D-Link BB-120 which required a firmware flash rendering it unuseable in Windows. They seem to sell them in the US (discontinued in Europe) although I saw on a consumer site from someone who bought one for the purpose of using it with OS X that they are different new versions of the old model and are often
advertised with with the old picture. Apple doesn't seem to support them anymore favouring built in cards
Apple Bluetooth kexts seem to use the Broadcom chipsets now, my Belkin is the same Broadcom
Of course if anyone can prove me wrong
The firmware flash doesn't run on SL, even if you extract the bits with pacifist.